Calibration of quantum measurement device

Abstract

A method is provided. The method includes: determining an order of a crosstalk noise of a quantum computer; determining a set of calibration circuits based on the order of the crosstalk noise; preparing a respective standard basis quantum state based on each calibration circuit in the set of calibration circuits, the quantum measurement device is repeatedly run for a predetermined number of times for each standard basis quantum state to measure the standard basis quantum state and to obtain a predetermined number of measurement results ; performing a statistic process on the obtained predetermined number of measurement results corresponding to each standard basis quantum state, to obtain a set of calibration data; determining a global generator based on a hardware topological structure of the quantum computer and the set of calibration data; and constructing a calibration matrix based on the global generator, so as to correct the measurement results of the quantum computer based on the calibration matrix.

1 . A method for calibrating a quantum measurement device, comprising:
 determining an order of a crosstalk noise of a quantum computer;   determining a set of calibration circuits based on the order of the crosstalk noise;   preparing a respective standard basis quantum state based on each calibration circuit in the set of calibration circuits, wherein for each standard basis quantum state, the quantum measurement device is repeatedly run for a predetermined number of times to measure the standard basis quantum state and to obtain a predetermined number of measurement results;   performing a statistic process on the obtained predetermined number of measurement results corresponding to each standard basis quantum state to obtain a set of calibration data;   determining a global generator based on a hardware topological structure of the quantum computer and the set of calibration data, wherein the global generator represents the crosstalk noise of the quantum computer determined based on the order of the crosstalk noise; and   constructing a calibration matrix based on the global generator, wherein a measurement result obtained by measuring the output result of the quantum computer by the quantum measuring device is corrected based on the calibration matrix.   
     
     
         2 . The method according to  claim 1 , wherein determining the global generator based on the hardware topological structure of the quantum computer and the set of calibration data comprises:
 initializing to obtain the global generator;   determining one or more qubit sets in each of which the crosstalk noise exists, according to the hardware topological structure and the order of the crosstalk noise;   determining a local generator corresponding to each of the one or more qubit sets based on the set of calibration data, wherein the local generator represents the crosstalk noise of the respective qubit set of the determined one or more qubit set; and   updating the global generator iteratively based on the local generators corresponding to the one or more qubit sets.   
     
     
         3 . The method according to  claim 2 , wherein the local generator corresponding to each of the one or more qubit sets is determined based on a following formula:         g   i     =         2   n     −   1   ⊕   i         i     −     i       i           where i = 0,1,..., 2 k  - 1, k is a quantity of qubits in the respective qubit set and k is a positive integer, and n is a quantity of qubits of the quantum computer.   
     
     
         4 . The method according to  claim 2 , wherein updating the global generator iteratively based on the local generators corresponding to the one or more qubit sets comprises:
 determining the calibration matrix corresponding to each of the one or more qubit sets;   determining, based on the calibration matrix, a set of weight coefficients for crosstalk noises each of which corresponds to each of the one or more qubit sets; and   updating the global generator iteratively, based on the local generator corresponding to each of one or more the qubit sets and the respective set of weight coefficients for crosstalk noises.   
     
     
         5 . The method according to  claim 4 , wherein the global generator G is updated iteratively based on the following formula:       G   =   G   +       ∑     i   =   0         2   k     −   1           λ   i       g   i               where k is a quantity of qubits in each of the qubit sets and k is a positive integer, and λ i  and g i  are respectively the ith weight coefficient of crosstalk noise and local generator corresponding to each of the qubit sets.   
     
     
         6 . The method according to  claim 1 , wherein the calibration matrix A is constructed based on the following formula:       A   =     e   G           where G is the global generator.   
     
     
         7 . The method according to  claim 4 , wherein the weight coefficient of a kth-order crosstalk noise is determined based on the following formula:                 λ   i             i   =   0         2   k     −   1       =   a   n   t   i   d   i   a   g       l   o   g         A   S                   where antidiag() represents acquiring all reverse diagonal elements.   
     
     
         8 . An electronic device, comprising:
 a memory storing one or more programs configured to be executed by one or more processors, the one or more programs including instructions for causing the electronic device to perform operations comprising:   determining an order of a crosstalk noise of a quantum computer;   determining a set of calibration circuits based on the order of the crosstalk noise;   preparing a respective standard basis quantum state based on each calibration circuit in the set of calibration circuits, wherein for each standard basis quantum state, the quantum measurement device is repeatedly run for a predetermined number of times to measure the standard basis quantum state and to obtain a predetermined number of measurement results;   performing a statistic process on the obtained predetermined number of measurement results corresponding to each standard basis quantum state to obtain a set of calibration data;   determining a global generator based on a hardware topological structure of the quantum computer and the set of calibration data, wherein the global generator represents the crosstalk noise of the quantum computer determined based on the order of the crosstalk noise; and   constructing a calibration matrix based on the global generator, wherein a measurement result obtained by measuring the output result of the quantum computer by the quantum measuring device is corrected based on the calibration matrix.   
     
     
         9 . The electronic device according to  claim 8 , wherein determining the global generator based on the hardware topological structure of the quantum computer and the set of calibration data comprises:
 initializing to obtain the global generator;   determining one or more qubit sets in each of which the crosstalk noise exists, according to the hardware topological structure and the order of the crosstalk noise;   determining a local generator corresponding to each of the one or more qubit sets based on the set of calibration data, wherein the local generator represents the crosstalk noise of the respective qubit set of the determined one or more qubit set; and   updating the global generator iteratively based on the local generators corresponding to the one or more qubit sets.   
     
     
         10 . The electronic device according to  claim 9 , wherein the local generator corresponding to each of the one or more qubit sets is determined based on a following formula:         g   i     =         2   n     −   1   ⊕   i         i     −     i       i           where i = 0,1,..., 2 k  -1, k is a quantity of qubits in the respective qubit set and k is a positive integer, and n is a quantity of qubits of the quantum computer.   
     
     
         11 . The electronic device according to  claim 9 , wherein updating the global generator iteratively based on the local generators corresponding to the one or more qubit sets comprises:
 determining the calibration matrix corresponding to each of the one or more qubit sets;   determining, based on the calibration matrix, a set of weight coefficients for crosstalk noises each of which corresponds to each of the one or more qubit sets; and   updating the global generator iteratively, based on the local generator corresponding to each of one or more the qubit sets and the respective set of weight coefficients for crosstalk noises.   
     
     
         12 . The electronic device according to  claim 11 , wherein the global generator G is updated iteratively based on the following formula:       G       =       G   +       ∑     i   =   0         2   k     −   1           λ   i       g   i               where k is a quantity of qubits in each of the qubit sets and k is a positive integer, and λ i  and g i  are respectively the ith weight coefficient of crosstalk noise and local generator corresponding to each of the qubit sets.   
     
     
         13 . The electronic device according to  claim 8 , wherein the calibration matrix A is constructed based on the following formula:       A   =     e   G           where G is the global generator.   
     
     
         14 . The electronic device according to  claim 11 , wherein the weight coefficient of a kth-order crosstalk noise is determined based on the following formula:                 λ   i             i   =   0         2   k     −   1       =   a   n   t   i   d   i   a   g       l   o   g         A   S                   where antidiag() represents acquiring all reverse diagonal elements.   
     
     
         15 . A non-transitory computer-readable storage medium that stores one or more programs comprising instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform operations comprising:
 determining an order of a crosstalk noise of a quantum computer;   determining a set of calibration circuits based on the order of the crosstalk noise;   preparing a respective standard basis quantum state based on each calibration circuit in the set of calibration circuits, wherein for each standard basis quantum state, the quantum measurement device is repeatedly run for a predetermined number of times to measure the standard basis quantum state and to obtain a predetermined number of measurement results;   performing a statistic process on the obtained predetermined number of measurement results corresponding to each standard basis quantum state to obtain a set of calibration data;   determining a global generator based on a hardware topological structure of the quantum computer and the set of calibration data, wherein the global generator represents the crosstalk noise of the quantum computer determined based on the order of the crosstalk noise; and   constructing a calibration matrix based on the global generator, wherein a measurement result obtained by measuring the output result of the quantum computer by the quantum measuring device is corrected based on the calibration matrix.   
     
     
         16 . The non-transitory computer-readable storage medium according to  claim 15 , wherein determining the global generator based on the hardware topological structure of the quantum computer and the set of calibration data comprises:
 initializing to obtain the global generator;   determining one or more qubit sets in each of which the crosstalk noise exists, according to the hardware topological structure and the order of the crosstalk noise;   determining a local generator corresponding to each of the one or more qubit sets based on the set of calibration data, wherein the local generator represents the crosstalk noise of the respective qubit set of the determined one or more qubit set; and   updating the global generator iteratively based on the local generators corresponding to the one or more qubit sets.   
     
     
         17 . The non-transitory computer-readable storage medium according to  claim 16 , wherein the local generator corresponding to each of the one or more qubit sets is determined based on a following formula:         g   i     =         2   n     −   1   ⊕     i       i         −         i       i               where i = 0,1, ..., 2 k  - 1, k is a quantity of qubits in the respective qubit set and k is a positive integer, and n is a quantity of qubits of the quantum computer.   
     
     
         18 . The non-transitory computer-readable storage medium according to  claim 16 , wherein updating the global generator iteratively based on the local generators corresponding to the one or more qubit sets comprises:
 determining the calibration matrix corresponding to each of the one or more qubit sets;   determining, based on the calibration matrix, a set of weight coefficients for crosstalk noises each of which corresponds to each of the one or more qubit sets; and   updating the global generator iteratively, based on the local generator corresponding to each of one or more the qubit sets and the respective set of weight coefficients for crosstalk noises.   
     
     
         19 . The non-transitory computer-readable storage medium according to  claim 18 , wherein the global generator G is updated iteratively based on the following formula:       G       =       G   +       ∑     i   =   0         2   k     −   1           λ   i       g   i               where k is a quantity of qubits in each of the qubit sets and k is a positive integer, and λ i  and g i  are respectively the ith weight coefficient of crosstalk noise and local generator corresponding to each of the qubit sets.   
     
     
         20 . The non-transitory computer-readable storage medium according to  claim 15 , wherein the calibration matrix A is constructed based on the following formula:       A   =     e   G           where G is the global generator.